Apparatus for control of typewriters



Nov. 28, 1950 c. T. JACKSON APPARATUS FOR CONTROL OF TYPEWRITERS FiledOct. 10, 1946 INVENTOR m 1K m J T n m. H w

ATTORNEY Patented Nov. 28, 1950 APPARATUS FOR CONTROL OF TYPEWRITERSCarlton '1. Jackson, Conesus, N. Y., assignor to International BusinessMachines Corporation, New York, N. Y., a corporation of New YorkApplication October 10,1946, Serial No. 702,521

12 Claims.

This invention relates to typewriting machines, and more particularly tocontact mechanism suitable for use in or with typewriting machines whichmay be wholly or partly electrically controlled.

An object is to provide an improved selective contact operatingmechanism suitable for use in or'for controlling power-operatedtypewriters and other keyboard machines or for remote control of suchmachines.

An object is to provide a key controlled power operated contact device.

An object is to provide a contact operating mechanism which is moreprecise and uniform in timing the contacts.

' Another object is to provide a contact operating mechanism whichenables very short periods of closure or opening of the contacts to beobtained.

An object is to provide a contact operating mechanism in which theduration of closure or opening of the contacts may be readily varied.

"An object is to improve contact mechanisms of the type disclosed inPatent 1,996,013.

In the past it has been customary to provide certain types of keyboardmachines, such as power operated typewriters and the like with contactmechanisms for the purpose of controlling electrical devices or circuitsselectively, for example, to control another machine remotely or tocontrol the impulse distributor of a printing telegraph system. Suchcontact mechanisms often take the form shown in the above patent inwhich a power operated device actuates contacts to close or open them,according to the requirements of the problems to be met.

- One of the disadvantages of the method of operating contacts asdisclosed in the above patent is that the contacts are operated only onthe forward stroke of the power operating device and are kept inoperated condition until the power operating device has been restored tothe point where the contacts were initially operated. As a result, theduration of the contacts is necessarily rather long and constitutes anappreciable percentage of the period of the cycle of the power operatingdevice because of the difliculty of adjusting the contacts preciselyenough to permit a shorter duration. Such a contact mechanism often isunsuitable because there are times when the circuit controlled by thecontacts must be made and broken, for example, before the mechanismoperated by the power device is fully operated. An illustration is wherea series of contact closures must be made during the course ofoperation' of a mechanism by a power device and the periods of closuremust not overlap. It is not possible to use contact operating mechanismslike the one disclosed in the patent for this purpose because theduration of closure is maintained during a part of the restoring strokeof the power device in consequence of the method of actuating thecontactsby means of a part connected to the power device which directlyengages the contacts when the power device has advanced a certaindistance in its cycle.

The present invention aims to supply the foregoing lack by providing acontact operating de-- vice which makes it possible to operate thecontacts completely before the power operating device has completed itsforward stroke and which will not operate the contacts while the powerdevice is restoring. Alternatively, the mechanisms described hereinaftermakes it possible to secure the opposite result of operating thecontacts during the restoring part of the cycle of operation of thepower device.

Another object is to provide for changing the duration of the contactclosure by a simplechange in the size of the principal member whichoperates the contacts.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in the accompanying drawings,which disclose, by way of example, the principle of theinvention and thebest mode, which has been contemplated, of applyin that principle.

In the drawings: Fig. 1 is a vertical section showing power operatingdevice for a typewriting machine with board controlled machine, forexample, a power operated typewriter, in which the instrumentalities ofthe machine, such as the type bars and:

other devices, are actuated by cam units like Ill of well knownconstruction which cam units cooperate with the usual power ggoller i IThe cam units H) are of the same type disclosed in Patent No. 1,996,013.When the key 52 controlling the cam unit I0 is depressed an extension- I2a thereon'cooperating with the detent lever I 0a of the cam unitreleases the cam Illb of the cam.

unit and allows a spring, not shown, to rotate the cam it?) slightly ina clockwise direction. This enables the power roller H to actuate thecam unit in a counterclockwise direction about the pivot wire 13,thereby drawing down the link Illa connected to the type bar or otherdevice.

It is desirable in the application of many keyboard controlled machines,such as power operated typewriters, to close circuits selectively undercontrol of the keys on the keyboard, as in many of the applications ofsuch machines some of the mechanisms are electrically operated and thecontrol circuits therefore must be established by the keys. A specificexample is the remote control of one typewriter by another typewriter,the first typewriter often closing circuits which control a transmissioncircuit of some kind to cause the second typewriter to function.

In the past the cam units Ill have been provided with extensions Iflcwhich directly actuate contacts, like the contacts C (Fig. 1) carried bymembers 15, by the engagement of a part of the extension, such as a pin,with a movable contact member l5 which thereby is directly moved by theextension to close contacts C. One of the drawbacks of such mechanismsis that the point of closure and duration of the contacts C is somewhatuncertain. In the drawings there is shown a means of operating thecontacts C which has been found to be more certain and which, withincertain limits permits the duration of the contacts to be readilycontrolled.

Instead of operating the upper contact member i5 of the contacts Cdirectly, as by means of an insulating pin or similar device on theextension lqc, there is provided a triangular contact operating element14 which preferably is made of an insulating material and is freelyrotatably mounted on a pin llld carried by the extension lilo. The topmember l5 for the contacts C may be bent at an angle at the point A andalso is provided with a stop plate B.

Normally one of the points of the triangular element 14 abuts the lefthand edge of the plate B with the bent portion A on the contact member15, lifting the lower right hand point of the contact operating element[4 slightly. A clearance is provided between the point of member l4nearest the plate to insure that the parts assume the position shown inFig. 1.

When the cam unit I is rocked in a counterclockwise direction asdescribed above, the lower right hand point of the element l4 engagesthe edge of plate B and, due to the fact that the pin id is above thelevel of plate B, the element M will be rotated. The extension Illc andelement I act like a toggle to depress the upper member 15 of contacts Cand close said contacts, as illustrated in Fig. 2, the parts being shownin approximately a dead center position in this figure.

With a little additional movement of the extension I0c in acounterclockwise direction, the spring pressure of the upper contactmember I5 on the element l4 causes rotation of the element M to theposition of Fig. 3, thus permitting the contacts to reopen. Theextension Inc may continue to the right (Fig. 3) on plate B as far asdesired but the contacts 0 will remain unaffected. On the return strokeof the extension Illc, the element l4 travels to the left and at firstmerely slides over the surface of the plate B but eventually the lowerleft hand point of element M in Fig. 3 will engage the bent portion Aand at about the same time the lower right hand point will slide off theplate B and the parts will reassume the position of Fig. 1.

The mechanism just described enables the contacts C to be operated onthe forward or counterclockwise stroke of the cam unit l0 while it isoperating the type bar or other instrumentality. With this mechanism thecontacts C may be normally open or normally closed or both, as desired,the drawings showing normally open contacts.

It will be understood, in the case of normally closed contacts, that theplate B and the bent portion A may be placed on the lower contact memberE5, in which case the contacts C will be opened when the cam unit inrocks counterclockwise.

There may be cases where it is desired that the contacts be operatedafter the device operated by the cam unit 10 has been operated. In otherwords, it may be desired, for example, to close the contacts C on thereturn stroke of the extension lBc. For this purpose the mechanism maybe arranged as shown in Fig. 4 in which the positions of the plate B andthe bent portion A are reversed and the element I4 normally occupies thesame position in Fig. 4 as it takes in Fig. 3.

When the extension lllc in Fig. 4 moves counterclockwise to the brokenline position (Fig. 4) it will be seen that the contacts C will not beoperated and will remain open, the upper contact member 15 merelyspringing upwardly slightly when the element 14 passes out of contactwith the plate B and takes the position shown in the broken lines. Onthe return stroke of the cam unit E0, in which the extension I00 movesto the left in Fig. 4, the lower left hand point of element [4 willengage the plate B and operate the contact C in exactly the same manneras described above, causing said contacts to be closed by the toggleaction occurring between the element It and the extension I80, thecontacts C reopening when the member I4 passes the dead center positionsufficiently to enable the r spring tension in the upper contact memberIE to rotate the element M back to approximately the position of Fig. 4.

By increasing the size of the element M or decreasing its size, as thecase may be, the duration of closure of the contacts C may be increasedor decreased at will. It is apparent that the shorter the sides of thetriangular element M the shorter the amount of time it will take tocause rotation of the member M the one-third of a revolution necessaryto eifect one full operation of the contacts 0. Another advantage of themechanism is that the points of closure may be more precisely controlledthan is the case with conventional mechanisms in which a stud carried bythe extension engages the contact member 15 directly. In such mechanismsusually one of the spring contact members i5 is bent to form an inclinedcam surface against which the pin on the extension bears to actuate thecontacts. Such elements are very indefinite in their timing, due to thefact that the resilient spring member becomes gradually bent out ofposition with the result that the time is liable to vary progressivelyand it is very difiicult to adjust such contacts to a precise timing. Itis also particularly difficult to adjust such contacts for durationbecause so much dependence has to be placed upon the rigidity of thespring contact member l5 and upon precise bending of the spring memberto get the necessary 5 adjustment. With the mechanism disclosed in thedrawing the adjustment of the spring members I5 is not critical.

The drawings show the element M as triangiilar in shape and the contactmember cooperating therewith as having the bent portion A. Neither ofthese structural characteristics of the illustrative embodiment of theinvention is essential. Where the triangular-element is used the pin Hidwill necessarily be located at the intersection of the bisectors of theangles of the triangle. This brings the pin [d very close to the uppercontact member l5, thereby making the force required to overturn theelement I4 relatively large in comparison with the force required withan element in the form of a square, the sides of which are the same inlength as the triangular element. In order to reduce this overturning inforce, in other words, to make the triangular element l4 overturn moreeasily, the bent portion A is provided to raise the pin llld slightly inrelation to the contact member. However, it has been found that, evenwithout the extension A, the mechanism operates successfully, althoughmore force is required to overturn the element [4. By making the elementM in the form of a square, the sides of which are the same length as thesides of element M in the drawings, the pin Hid will be spaced away fromthe contact member with which it cooperates the distance of one-half thelength of a side which is considerably greater than the spacing shown inFig. 1. This makes the element l4 much easier to overturn and in caseswhere there is a heavy burden on the cam unit to operate the desiredmechanism, and the contacts C at the same time, the square form ofelement lfld may prove very desirable.

By positioning the plate B at various points along the upper contactmember i5 in Figs. 1 and 4 the point at which the contacts 0 areoperated may be varied. For example, in Fig. 1 the plate 14 might beshifted further to the right or shortened so that the contacts C will beoperated nearer the end of the stroke of the cam unit I0. Similarly, inFig. 4 the plate B may be shortened or shifted to the right so that thecontacts C are closed only when the cam unit It is fully restored.

It is quite apparent from the foregoing that r the point of operationand duration of contact of the contacts may be controlled over a widerange and be made very precise, particularly in the case of normallyclosed contacts which it is desired to open at a very precise point inthe operation of the cam unit. In the timing of electrically controlleddevices, sometimes the closing time is not particularly important butthe point at which the contacts are opened may be very critical. In thecase of the mechanism disclosed above, 0W- ing to the snap action whichoccurs at the point where element 14 overturns, it is possible to get avery precise reopening or reclosure of the contacts C, particularly ifthe triangular element I4 is made as small as possible to reduce theoverturning time to a very small value. In the arrangement shown in thedrawings, the closing time may not be very precise and may varysomewhat, due to wear at the vertices of the triangular element but,owing to the snap action occurring when the element I4 is overturned,the reopening of the contacts will be very precise and quick. It is thusapparent that a relatively large amount of control over the precision ofoperation of contacts C, both in point of time and duration, may

be obtained by varying the size of the element N, the number of sideswhich it may have and the relative positions of the plate B.

While there have been shown and described and pointed out thefundamental novel features of the invention, as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaims.

What is claimed is:

l. A key-controlled power-operated switching device for typewriting andother ofiice machines comprising contact means including a contactoperating element having a guiding surface and an abutment, a keycontrolled power operated device having an oscillatable member, and apolygonal contact actuating element mounted for rotation on said memberand having one polygonal side engaging said surface, said element, whensaid member is oscillated, engaging said abutment and having rotationimparted in consequence of motion of said member while said elementengages said abutment, said rotation'actuating the contact means.

2. A contact mechanism comprising a contact actuating blade having anabutment, a power device including an element having a to-and-fromotion, and a polygonal contact actuating member rotatably mounted onsaid element and having its corners engageable with said abutment androtating in consequence of such engagement to actuate said contactblade.

3. A contact mechanism comprising a contact operating device having ato-and-fro motion, a polygonal contact actuating element rotatable onsaid device, contact means, and a contact member engageable by saidelement during a part of the motion of said device and having a portionshaped to act as a fulcrum for any one of the vertices of the polygonalelement and cause rotation of the latter by engagement with a vertex ofthe polygonal element, said rotation displacing said member sufficientlyto operate the contact means.

4. In a contact mechanism, an invariably 0perated member having a fixedoperating cycle between two limits of motion, a contact member, and arotatable element carried by said operated member and having a series ofcontact operating projections engageable one-at-a-time with said contactmember at a definite fulcrum point between said limits of motion so asto be partly rotated in consequence of such engagement to therebyoperate said contact member.

5. A contact mechanism comprising a vibratory actuating member, a starwheel rotatable on said member, and a contact member shaped to pivotallyengage one of the points of the star wheel with each vibration of theactuating member and cause the star wheel to rotate and thereby operatethe contact member.

6. A circuit controlling mechanism comprising an oscillatable actuatingdevice, a rotary member on said device having a series of radiatingprojections, and a contact member movable betwen circuit opening andcircuit closing positions and having a stop portion pivotally engagingone of said projections during each oscillation of said device to causerotation of said rotary member and at the same time being displaced bysaid rotation from one of said positions to the other.

7. A key-controlled power-operated switching mechanism for typewritersand other office machines comprising a key-controlled power operateddevice having an oscillatable member, a switch including a switchactuating member, and a star wheel rotatable on said oscillatablemember, one of the points of said star wheel being pivotally engageablewith the switch actuating member at a definite point in the cycle of theoscillatable member to cause rotation of the star wheel and therebyoperate the switch through said actuating member.

8. A contact mechanism comprising a contact actuating blade having aStop portion, a power device including an element having a fixed travelbetween two limits of operation, and a star wheel rotatably mounted onsaid element, one of the points of said star wheel pivotally engagingsaid stop portion during the travel of said element to cause rotation ofthe star wheel and thereby effect an operation of the contact actuatingblade.

9. In a contact actuating mechanism, a contact Operating deviceincluding an element having a travel between two extremes of movement, acontact controlling member rotatably mounted on said element andcomprising a symmetrical multi-lobed Wheel, and switching meansincluding a member adapted to be displaced by pivotal engagement of apredetermined portion of the second member with one of said lobes andsubsequent rotation of the controlling member.

10. A contact mechanism comprising a con tact actuating device having aninvariable excursion between two limits, a multi-pointed elementpivotally mounted on said device, and a contact controlling memberhaving a fulcrum portion engageable by one of the points of said elementat a predetermined position in the excursion of said device andeffecting rotation of said element, said member being displaced by saidrotation.

11. a power-operated typewriter or like machine, power operatingmechanism including a power roller and a cam unit oscillatable by saidroller, a toothed member rotatable on said unit and movable therewith inan arc of a circle, and a contact controlling member positioned to beengaged by one of the teeth of the toothed memher during an oscillationof the cam unit by the power roller and displaced thereby, said memberrotating said toothed member suificiently to place another tooth inposition to operate said member the next time the cam unit is oscillatedby the power roller.

12. A contact mechanism comprising contact means, a member for actuatingthe contact means, a member movable back-and-forth between two limits ofmotion; and an element pivotally connected to the second member andhaving a series of projections successively pivotally engageable one ata time with a fixed part of the first member, said element, inconsequence of said engagement, being rotated to bring anotherprojection into position for the next operation and at the same time tooperate said contact actuating member.

CARLTON T. JACKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 13,081 Miller Feb. 8, 19101,839,916 Ehrlich Jan. 5, 1932 1,862,006 Collins June 7, 1932 1,996,013Thompson Mar. 26, 1935 FOREIGN PATENTS Number Country Date 108,802Switzerland Apr. 4, 1923 665,793 France May 13, 1929

